wanted( EU) : repair prodigy for Apogee AD16X/ no schematic

[Whoops]

I sometimes have HF clicking during playback when I turn my DA16x on.
After switching the unit Off and On again it disappears. (Most of the time)
Anyone had this fault here?

Try to record that issue

Are you sure it's not a clocking problem?

 

[DerEber]

Thanks for your answer.
It def. sounds like a clocking issue. Exact that sound.

The odd thing is that it goes away after I turn the DA16x off and on once or sometimes twice.
My setup is a Mytec 2ch AD that clocks the RME Adat Card and the DA16X and the AD16X via short BNC WC.
So this is not a too complicated setup with a clear master.

Also it happens only on startup. I never have problems in between a session.
Although the crackling is not always the same amount on startup. Sometimes no issues.

So the real problem is me starting to get paranoid that the AD will develop the same behavior.
In my current workflow this will not be noticed by me for long. (Now lets do the real mix )
And also of cause I fear from total breakdown of the DA16X.
16 Outs in that league should be quite costly. If I research for the usual quality converters I easily exceed the 2000€

But you'r right maybe it is time to check my whole clocking. Say clock the converters from ADAT or change the cables.
Could a bad battery also be a suspect? Sometimes the converters loose their parameters.....

I'll report back.
Greetings!

 

[scott2000]

I guess process of elimination..... Get rid of the Mytek first and see if it disappears...... etc.....

Good Luck!! Has to be something......

 

[AK79]

once you can rule out the clocking you should have a look at the powersupply.

br
Arne

 

[metalb00b00]

PCB probably with 3 or 4 layers, all SMD components, no schematics, chips unmarked

Let's see, I will let you know my findings

Are you sure they are unmarked? Have not seen any manufacturer do this these days.
Most often the marking is not (or barely) visible because of moisture.
Just swab it with a q-tip and a tiny bit of white thermal paste.

 

[Khron]

I think i've mentioned it before here, but i think i've only seen "blank" chips in cut-rate far-eastern made gear; never in "brand name" stuff.

Markings can indeed be sometimes "interesting" to see, unless you catch both the light and the chip surface at the right angle...

Are you sure they are unmarked? Have not seen any manufacturer do this these days.
Most often the marking is not (or barely) visible because of moisture.
Just swab it with a q-tip and a tiny bit of white thermal paste.

 

[metalb00b00]

I think i've mentioned it before here, but i think i've only seen "blank" chips in cut-rate far-eastern made gear; never in "brand name" stuff.

Markings can indeed be sometimes "interesting" to see, unless you catch both the light and the chip surface at the right angle...

I have broke and took apart many electronics stuff Made in China, including those as low as $1 a piece, and I have not yet encountered unmarked chips in it. Even the low quality $5 switched power supply adapter that I repaired last month, which to many is considered a trash because nowadays people just throw it away after it's broken. And I bet Solid State Logic even got it for much less than that because they buy in bulk (and then sell it on their web store for $116, heh)

 

[Khron]

Big Clive over on Youtube has taken apart loads of cheapie Chinese gadgets, many of which have "anonymous" 8-pin / 14-pin / 16-pin microcontrollers.  There are a couple of those "blank" chips in-between the line-level and RF sections in some cheap Takstar wireless sets too.

 

[Joseph813]

Hello,
I would like to ask a favor to anyone who would like to post a photo of the interior of an apogee ad16x, please
I need the code of 2 mosfets located under the gray flat and the connector of the psu. I would be really grateful !!! Thank you all !!!!!!

 

[Joseph813]

Hello,
I would like to ask a favor to anyone who would like to post a photo of the interior of an apogee ad16x, please
I need the code of 2 mosfets located under the gray flat and the connector of the psu. I would be really grateful !!! Thank you all !!!!!!

 

[Whoops]

I had some photos of the AD16 interior but I'm not finding them at the moment.

If I find them I can send them to you

 

[Whoops]

It's a shame that after so many years we can't still get any Apogee Schematic

 

[Joey777]

I used RME for a few years. RME can be a little finiky with clocking from other sources. Maybe I am imagining it, but I had a muliface, hamerfall, Raydat and a handful of others. The PCI / E cards never seem to like clocking coming from anything other than an RME piece of hardware. Sometimes having to use wordclock cables with T pieces and resisters to terminate the out puts when running multiple units on a one way loop ( I don't know if that makes sense ) I had 8 ADI 8DS and 2 RayDats at one point and the clocking was horrible with wordclock no matter how I configured it. Using the Raydat as master / internal and telling all the ADAT attached gear to clock from ADAT worked. Some other set-ups worked better when the pci /e card was set to slave, with ADAT IN ( always the first ADAT port, for some reason ) and the clocking was sent to it via ADAT from another converter. I had real bad memories of clocking with RME in a multi set-up. The converters I found were really good and the drivers rock solid. There is a small prog that comes from RME called DigiCheck Test, Measurement and Analysis Tool for RME Audio Interfaces - RME Audio Interfaces | Format Converters | Preamps | Network Audio & MADI Solutions you can use this to check for clocking issues. Good luck

 

[bundy]

I'm currently troubleshooting a dead channel on an AD-16X.
Are there still no resources available for this unit?

 

[Khron]

I'm currently troubleshooting a dead channel on an AD-16X.
Are there still no resources available for this unit?

Signal generator connected to the bad channel and a good one, oscilloscope and comparisons.

 

[HelioRibeiro]

Hello.
I write this comment because I found this topic a few days ago when I was trying to solve the same problem with my two Apogee DA16x converters.
I didn't understand anything about electronics but I tried to solve it and I managed to do it.

Converter 1:
Channel 5 dead.
Channel 15 noise (around 30 Hz).

Converter 2:
Channel 12 with noise (around 30hz)
After having replaced all the tantulum SMD 10uf capacitors and some opamps, I concluded that:

DEAD CHANNEL (no output signal):
10uf capacitor (ref 106D) shorted.
Normally one of the 1ohm SMD resistors at the channel input also burns out when this happens.
In this case, see if any of the two 1ohm SMD resistors at the channel input (analog part) measure a high resistivity, if so, replace it.
Then, as the switched off equipment measures continuity across all the capacitors on the channel, 3 or 4 are supposed to be shorted but only one of them is actually shorted.
I replaced all the shorted ones and then confirmed that there were indeed damaged capacitors.
(To find which of the capacitors is failing, simply unsolder one of the legs of each one and test with a multimeter to see if there is still a short in the channel.)
Problem solved by replacing the shorted capacitor.

NOISE IN THE CHANNEL:
Case 1) I started by replacing all the 10uf capacitors on the channel but it still made noise.
It was solved by replacing the 4 channel opamps that are closest to the output.
Possibly only one of them was damaged but it replaced all 4 (may be one of the two OP275G or the OP2177).
I know I can test now the opamps that they are off the board but I haven't even tried.
Problem solved after replacing 4 ompaps (OP2177,(2x) OP275G, TLE2071)


Case 2)
Channel opamps in channel converter direction->Output:
(1x) opa4134ua
(1x) OP2177
(2x) OP275G
(1x) TLE2071
In my DAW (Cubase) I put a 100Hz signal on all channels of the converter and compared the noisy channel with a good channel with an osciloscope.
On the noisy channel I saw noise on the oscilloscope in near all opamps, I assumed it would be the first one, the one closest to the channel converter, I replaced the opa4134UA opamp and the noise remained.
I replaced the other 3 opamps and it was resolved.
By this I mean that apparently a problem in an opamp close to the output also generates noise in the previous opamps.
In this case the oscilloscope was of no use to me.
Problem solved after replacing 3 ompaps (OP2177,(2x) OP275G )

Apparently for a channel without output it is necessary to replace 10uf capacitors.
For a noisy channel it will be a problem with the opamps.
If the noise still remains, it seems to me that there is a capacitor damaging the opamps.
(Always replacing the channel 10uf capacitors will be best solution - it's easy to do even without a hot air gun)

I hope I helped even if I don't understand electronics.
I had a problem to solve and I had to solve it myself. I'm Portuguese, before I contacted Apogee and they didn't help me at all.
They just told me that I would have to send the equipment to the USA, pay shipping to send and to return it, pay a fee of 95 dollars per unit and to repair each could cost up to 599 dollars.


I have a third Apogee DA16x that doesn't work and that I'm trying to repair.
There is a short in some component apparently in the main circuit of the board.
I see several components shorting with the multimeter.
One of the FDS6982S Mosfets was burned and I replaced it, the short continues.
The short is being caused by another component and not by the MOSFET.
If I turn on the converter the MOSFET will burn out again.

I don't even know how to open the circuit from the main part of the board (where the PSU plug is connected) to the digital part where there are also shorted components.
The PSU is working correctly.

If anyone knows something that I can test I would appreciate the help.

Hélio

 

[pucho812]

Apogee is not the only company that does not hand out schematics to their techs. In the current age you can see that as two ways.
1.they are afraid schematics will get out and cloned
2.hinders the repair process.
Both are not good.
As always with unknown gear or schematics we know enough that we can test for shorted caps and resistors. I have found that to be more common then anything else.

 

[Whoops]

Hello.
I write this comment because I found this topic a few days ago when I was trying to solve the same problem with my two Apogee DA16x converters.
I didn't understand anything about electronics but I tried to solve it and I managed to do it.

Olá Hélio,
cumprimentos de Portugal, há muito poucos Portugueses no forum por isso fico contente por se ter juntado mais um membro do nosso País,
e desejo que tenhas uma boa recepção no forum e que te divirtas.

Great information in your post, I'm really happy that you were able to fix the channels.
There's a lot of faulty Apogee AD8000 and AD16 around, the lack of schematics and the fact that some ICs had the lettering removed makes it really hard for people to fix them.
Many people would love to repair their Apogee converters because these series still sound very good today, so you post and your info are highly valuable

 

[Michael Tibes]

...unless one of you guys reverse-engineer it...

Jakob E.

I have a few AD 16 with no x, which I am fixing. I beliebe that the x version might be similar as a general concept. I am not in the Studio these days, but I can post my partial reverse engineered schematic in maybe two weeks. My units have three error points: first the bypass caps. They create a short and blow the 10r resistor, so the whole output loses a rail. Then there are two dc servos, one main and one for the balance between the in/outphase of the balanced outputs. If I remember right there might be 100n caps failing, fu..ing the servo. I managed to get all my outs working again and fixed all the main servos, but still have the sind servo left to do.

 

[Michael Tibes]

The signal path on my units is entirely balanced, in case anyone tries to look into it. That’s different from the data sheets recommendation.